1. Area of Invention
The instant invention relates to athletic shoes having resilient springs, or spring equivalents, within the heel thereof.
2. Prior Art
The instant invention comprises an improvement of my U.S. Pat. No. 5,544,431 (1996) entitled Shock Absorbing Shoe with Adjustable Insert and also comprises an improvement over the invention of U.S. Pat. No. 5,343,639 (1994) to Kilgore, et al, entitled Shoe with Improved Midsole and over U.S. Pat. No. 6,006,449 (1999) to Orlowski, et al entitled Footwear Having Spring Assemblies In the Insoles Thereof.
Numerous patents exist in the field of footwear. Therein, a primary purpose thereof is to protect the foot from injury. Further, the sole of the shoe provides traction and cushioning. In the context of an athletic shoe, various attempts have been made in the prior art to incorporate a spring, a spring module, or spring equivalent into either or both the heel or forefoot thereof. However, spring based athletic shoes of the past were mainly novelty products having an unpredictable platform that would react unpredictably to various forces provided, this in direct relation to the impact applied by the heel of the foot to the spring, spring module or spring equivalent. Accordingly, a primary problem in the incorporation of springs into the heel of a shoe has been that of controllability thereof.
U.S. Pat. No. 5,282,325 discloses a sport shoe having a spring disposed in the sole of the shoe in which the spring operates to provide bias to the foot in a raised position and cushioning of the shoe against shock from the ground. The spring employed therein is a torsion spring positional along the longitudinal axis disposed horizontal to the ground and using the spring constant to resist flexing of the spring. The above referenced U.S. patent to Kilgore provides an improved midsole and heel utilizes a group of hollow cylindrical columns within the heel portion and, therein, the use of either gas bladders of a micro-cellular foam-like material therein to provide a desired degree of stiffness to the respective columns responsive to impact thereupon. Given the essentially passive nature of the air bladder or micro cellular supported columns of said system, the end result is a shoe having improved cushioning but, however, lacking the requisite degree of resilient spring-action for use in certain sports such as basketball.
In my said U.S. Pat. No. 5,544,431 (1996) is described a shock absorbing adjustable insert for use within the heel of the sole which comprises a spring module system having particular value in certain activities such as basketball and other jumping sports. Therein, the spring action operates as a shock absorber for the foot and provides an accelerating spring action following the compression which precedes any jumping motion of an athlete. The instant invention may, thereby, be viewed as an integration of the spring and spring platform support features of my said U.S. Pat. No. 5,544,431 with the use of compressible vertical columns as is taught by said Kilgore. Additionally, the instant invention reflects a recognition that, given the existence of contemporary high impact, high resilient polymeric materials, a considerable range of spring equivalence exists which, in terms of both spring constant and spring rate, can behave in a comparable yet more controllable fashion than classical springs.
My invention relates to an athletic shoe having stabilized discreet resilient elements substantially within a horizontal chamber substantially within a heel portion of a midsole thereof, said chamber having atmospheric communication at lateral sides thereof. The improvement more particularly comprises (a midsole chamber having an upper substantially rigid horizontal plate with at least four apertures therein) a lower substantially rigid horizontal support plate with a corresponding plurality of at least four apertures therein. Also provided are flexible resilient unitary sleeves integrally joining respective vertical pairs of said apertures of said upper and lower plates respectively. Yet further provided are solid resilient means disposed within each of said sleeves, said resilient means each having a greater spring constant and spring rate than that of said resilient sleeves, whereby directionality of said spring rate is controlled by said sleeves. Means are provided for securing said horizontal chamber between upper and lower soles of the shoe.
It is accordingly a primary object of the present invention to provide an athletic shoe adapted to relieve shock loads experienced by the wearer and to maximize the spring effect of the heel thereof.
It is another object to provide an improved athletic shoe using spring elements or spring element equivalents having improved stability relative to shoe components above and below such elements.
It is a further object of the invention to provide an athletic shoe particularly adapted for use in basketball and other jumping sports.
The above and yet other objects and advantages of the present invention will become apparent from the hereinafter set forth Brief Description of the Drawings, Detailed Description of the Invention, and Claims appended herewith.